Granular Cell Variant of Atypical Fibroxanthoma

Leiomyosarcoma of the great saphenous vein (vena saphena magna) with granular cell change: Report of a superficial neoplasm

The great saphenous vein (GSV) corresponds to the main superficial large-caliber vessel affected by leiomyosarcoma (LMS). Given its superficial location and because signs of vascular origin may not be clinically apparent, LMS of the GSV may be misinterpreted clinically as superficial nonvascular soft tissue mass. Herein, we report a case on the distal portion of the right GSV of a 57-year-old man. The histopathological recognition of a large-caliber vein-associated LMS (with granular cell change) in an incisional biopsy specimen was crucial to guide radiological evaluation and confirmation of a superficial vascular LMS before surgical treatment. Recognizing this entity in small biopsies is important as its surgical treatment and prognosis differ substantially from nonvascular superficial (ie, subcutaneous and dermal) LMSs. In addition, because vascular LMSs can involve long vessel segments, underestimation of extent of disease is a risk. To the best of our knowledge, granular cell change has not been documented in LMS of the GSV.

Atypical fibroxanthoma: new insights

Atypical fibroxanthoma (AFX) is an ultraviolet radiation-associated dermal neoplasm. To address the clinicopathologic and molecular features of this particular neoplasm. The author conducted a literature review using PubMed searching for articles relating to AFX. AFX usually appears as a rapidly growing nodular or nodulo-ulcerative lesion. It occurs on sun-exposed skin of elderly peoples. AFX may be composed predominantly of pleomorphic, spindle, epithelioid cells, or admixture of these cells. The differential diagnosis of AFX includes pleomorphic dermal sarcoma, squamous cell carcinoma, malignant melanoma and leiomyosarcoma. Several observations favor a mesenchymal origin for AFX. These reviews address the clinicopathologic features, molecular pathology, prognosis and treatment of this neoplasm.

Pleomorphic dermal neoplasms: a review

Pleomorphic neoplasms are typically associated with high-grade malignant behavior, but this does not readily apply to primary cutaneous tumors. Despite morphologic features suggestive of malignancy, atypical fibroxanthoma, the classic example of a pleomorphic dermal neoplasm, is characterized by indolent clinical behavior. Atypical fibroxanthoma is a distinctive clinicopathologic disease affecting sun-damaged skin of elderly males. Histologically, it is often ulcerated and dermal based with pushing growth, characterized by a sheet-like and fascicular growth of pleomorphic epithelioid, spindled, and multinucleated tumor cells with brisk and atypical mitotic activity. However, no positive discriminatory histologic or immunohistochemical features exist. Its diagnosis is one exclusion with a wide differential diagnosis, mainly including other mesenchymal, melanocytic, and epithelial neoplasms. Particular considerations are pleomorphic dermal sarcoma, invasive melanoma, squamous cell carcinoma, metaplastic carcinoma, poorly differentiated cutaneous angiosarcoma, cutaneous leiomyosarcoma, myxofibrosarcoma, variants of fibrous histiocytoma (FH), pleomorphic fibroma, and non-neural granular cell tumor. The behavior of these tumors is varied and ranges from outright malignant to entirely benign, requiring confident diagnosis to reliably predict behavior and guide treatment. Although challenging, because of significant clinical and pathologic overlap, it is usually possible to establish a definitive diagnosis when attention is paid to the often subtle differentiating features. This requires careful tumor sampling, recognition of the subtle distinguishing morphologic features, judicious use and analysis of immunohistochemistry, and interpretation of the findings in the appropriate clinical setting.

Superficial CD34-positive fibroblastic tumor: report of 18 cases of a distinctive low-grade mesenchymal neoplasm of intermediate (borderline) malignancy

Fibroblastic mesenchymal tumors show a spectrum of biological behavior, from benign to fully malignant. We report our experience of two decades with a distinctive, previously undescribed low-grade fibroblastic tumor of the superficial soft tissues. Eighteen cases were identified within our consultation files, previously coded as 'low-grade sarcoma, not further classified' and 'malignant fibrous histiocytoma, low grade'. The tumors occurred in adults (median age 38 years, range 20-76 years) of either sex (10 males and 8 females), ranged in size from 1.5 to 10 cm (mean 4.1 cm), and were confined to the superficial soft tissues of the thigh (N=5), knee (N=2), and other sites. Histological features included a fascicular growth pattern of the neoplastic spindled cells with striking, often bizarre cellular pleomorphism and variably prominent nucleoli. Necrosis was seen in one case. All cases showed strong, diffuse CD34 positivity and 68% of tested cases demonstrated focal cytokeratin expression. Desmin, ERG, FLI-1, smooth muscle actin, and S100 protein were negative. TP53 overexpression was absent. Fluorescence in-situ hybridization studies for TGFBR3 and/or MGEA5 rearrangements were negative in all tested cases. Clinical follow-up was available in 13 patients (median duration of 24 months; range 1-104 months). Twelve of 13 patients had no disease recurrence. One patient had regional lymph node metastases, 7 years after incomplete excision of the primary tumor. All patients are currently alive and disease free. The unique clinicopathological features of superficial CD34-positive fibroblastic tumor define them as a novel subset of low-grade fibroblastic neoplasms, best considered to be of borderline malignancy.

Granular cell atypical fibroxanthoma: case report and review of the literature

We present a case of granular cell atypical fibroxanthoma of the scalp. The neoplasm occurred as a tender nodule on the frontal scalp of an 82-year-old Caucasian man. Histology demonstrated a diffuse proliferation of atypical epithelioid cells with abundant granular cytoplasm. Many of the cells had large irregular nuclei and atypical mitotic figures were present. Immunohistochemical stains were positive for CD68 and procollagen 1 and negative for cytokeratin, HMB-45 and S-100 protein. The granular cell phenotype has been observed in other cutaneous neoplasms including granular cell tumors, dermatofibromas, dermatofibrosarcoma protuberans, fibrous papules, basal cell carcinomas, leiomyosarcomas, angiosarcomas and primitive polypoid granular cell tumors. We discuss the differential diagnosis and review the previously reported cases of this rare variant of atypical fibroxanthoma.

Cutaneous fibrohistiocytic tumours - an update

The term 'fibrohistiocytic' tumour is a descriptive designation without histogenetic connotation for a group of heterogeneous lesions that share morphological features of histiocytes and fibroblasts on light microscopy. However, over the years it has become apparent that many so-called 'fibrohistiocytic' tumours are largely composed of relatively undifferentiated mesenchymal cells, but can also show areas of myofibroblastic differentiation. This review focuses on the clinical and histological features as well as differential diagnosis of so-called fibrohistiocytic tumours. Special emphasis is given to more recently described histological variants of fibrous histiocytoma, e.g. cellular, epithelioid, aneurysmal and atypical fibrous histiocytoma, to angiomatous and plexiform fibrous histocytoma (plexiform fibrohistiocytic tumour), lesions that are not true variants of fibrous histiocytomas but have erroneously been designated such, and to atypical fibroxanthoma. The literature on metastasizing fibrous histiocytoma is also reviewed.

Morphological and immunohistochemical characteristics of atypical fibroxanthoma with a special emphasis on potential diagnostic pitfalls: a review

The present manuscript gives emphasis on recognizing different morphological variants of atypical fibroxanthoma (AFX), on validation of immunohistochemical markers and on discussing potential diagnostic pitfalls.

MATERIAL AND METHODS

Histological features analyzed in 66 AFXs were: ulceration, morphological variants, growth pattern, location in the skin and vascular/perineural invasion. The antibodies used were CK-MNF116, CK-AE1/AE3, S100, smooth muscle actin, desmin, CD31 and EMA.

RESULTS

The study included 59 males, 7 females, aged 55-95 years, mean 77 years. All developed on sun damaged skin. Ulceration was present in 50%. Morphological patterns were pleomorphic spindle and epithelioid cells (60.6%), predominantly spindle cells (19.7%), purely spindle-cells (13.6%), and predominantly epithelioid cells (6.1%). Most were localized in the dermis (57.6%). An expansile (36.4%) rather than infiltrative (6.1%) growth into superficial subcutis was also noted. No vascular/perineural invasion was seen. Additional changes were hemorrhagic and pseudoangiomatous areas (24.2%), granular cell change (22.7%), keloid-like areas (9.1%), myxoid change (7.6%), osteoclast-like giant cells (6.1%) and clear cell change (4.6%). AFXs were consistently negative for S100, CK-MNF116, CK-AE1/AE3 and desmin. Focal positivity for SMA (45.2%), EMA (24.4%) and CD 31 (9.5%) was seen.

CONCLUSIONS

A diagnosis of AFX is still made by exclusion of other malignant neoplasms with similar morphology. Immunohistochemistry plays a crucial role in this distinction, but can also be misleading. This study expands the spectrum of non-vascular CD31 positive tumors.

Fibrous papule of the face with granular cells

Fibrous papule of the face is a common benign lesion located most often on the nose. It presents usually as a single small, firm, skin-coloured papule and is often misdiagnosed as melanocytic naevus, wart or small nodular basal cell carcinoma. Histopathologically, the lesions are characterized by involvement of the upper dermis by a fibrovascular proliferation and scattered triangular or stellate, often multinucleated cells. Uncommon histopathologic variants of fibrous papule of the face include hypercellular, clear-cell, pleomorphic, pigmented, inflammatory and granular-cell types. We present here a patient with the syndrome of familial cancer and fibrous papule of the face with granular cells. The granules stained strongly with PAS stain, as well as with CD68 and NKI/C3 immunostains, whereas S-100 protein resulted negative. In our patient the mutations in the 2 most often affected DNA mismatch repair genes of Muir-Torre syndrome were not found, therefore the origin of the familial cancer syndrome remains unknown. Probably the occurrence of the granular-cell fibrous papule of the face was coincidental.

Granular Cell Atypical Fibroxanthoma: Report of Two Cases

Two cases of an uncommon histopathological variant of atypical fibroxanthoma (AFX) are described. Even though both lesions presented as clinically conventional atypical fibroxanthoma, histopathology disclosed a neoplasm composed of cells with granular change that was negative for S100 staining, and showed prominent pleomorphism, severe nuclear atypia, and a high mitotic index. Degenerative change may explain the granular phenotype in these two cases of AFX. The differential diagnosis with primitive nonneural granular cell tumor is discussed.

Frequent positive staining with NKI/C3 in normal and neoplastic tissues limits its usefulness in the diagnosis of cellular neurothekeoma

NKI/C3 originally was described as a marker for melanoma. Recently, it resurfaced as a marker to separate cellular neurothekeoma from other dermal tumors in the differential diagnosis. To determine the sensitivity and specificity of NKI/C3, we evaluated its staining pattern in 709 normal and neoplastic tissues, including 92 dermal tumors, using tissue microarrays and conventional sections. We found that although NKI/C3 is positive in only a few normal tissues, it stains a broad spectrum of neoplastic tissues. NKI/C3 is also positive in many dermal tumors of possible histiocytic origin, including juvenile xanthogranuloma (6/10), atypical fibroxanthoma (4/12), cellular fibrous histiocytoma (5/10), reticulohistiocytoma (3/6), and xanthoma (8/10). However, it is negative in epithelioid cell histiocytomas (0/7) and Langerhans cell histiocytosis (0/9). Given the wide spectrum of positive staining in morphologic mimics of cellular neurothekeomas, pathologists should be cautious when making this diagnosis based solely on positive staining with NKI/C3.

Dermal non-neural granular cell tumour (so-called primitive polypoid granular cell tumour): a distinctive entity further delineated in a clinicopathological study of 11 cases

AIMS

Cutaneous and soft tissue granular cell tumour is a well-characterized benign neoplasm of neural origin. However, there remains a subcategory of granular cell tumour, first described by Le Boit as 'primitive polypoid granular cell tumour', that shows no obvious line of differentiation. The aim of this study is to further the characterization of this lesion by undertaking a clinicopathological review.

METHODS AND RESULTS

Eleven cases of dermal non-neural granular cell tumour were retrieved from one of the authors referral archives (E.C.) and both the histology and immunohistochemistry reviewed. Clinical data with follow-up were obtained from the referring pathologists. The lesions most commonly occurred in young to middle-aged adults (nine cases, median = 33 years, age range 6-56 years), with a slight female predominance. They presented as painless nodules, mainly on the extremities or face. Local excision was the treatment of choice and up to date follow-up reveals no sign of recurrence. Histologically, eight cases were polypoid, while three cases were endophytic. The tumours were composed of elongated spindle-shaped to polygonal or round cells with prominent granular cell change, and tumour nuclei showing mild focal atypia to rare moderate atypia. Mitotic activity ranged from one to nine mitoses per 10 high-power fields (median = 2, mean = 3.8). Immunohistochemical labelling of the tumour cells demonstrated expression for NKI-C3 (n = 11), focal, weak positivity for CD68 (n = 10) and FXIIIa (n = 2). There was negative staining for S100 protein, smooth muscle actin, Melan-A, CD34, desmin and cytokeratin.

CONCLUSIONS

This analysis of 11 cases contributes to the characterization of this recently described entity, which despite some atypical histological features and no obvious line of differentiation, behaves in a completely indolent fashion.

Primitive Nonneural Granular Cell Tumors of Skin

A rare subset of distinctive cutaneous nonneural granular cell tumors was described by LeBoit et al in 1991 and termed "primitive polypoid granular-cell tumor." Herein, we report our experience with 13 similar, distinctive nonneural granular cell tumors. Affected patients included 7 males and 6 females ranging in age from 5 to 83 years (mean, 25 years; median, 16 years). These cutaneous lesions involved the back (5 cases), neck, shoulder, thigh (2 cases each), chin, and elbow (1 case each). Clinically described as smooth, nontender cutaneous nodules, the tumors ranged in size from 0.2 to 2.8 cm (median, 0.8 cm) and were present from months to years before excision. Mitoses numbered from 1 to 6 per mm (median, 2). Eight of the lesions were polypoid, based in the papillary dermis with extension to the superficial dermis and associated with an epithelial collarette. Five of the lesions were situated deeper in the reticular dermis with limited extension into the subcutis but clinically were also nodular. All the tumors were well circumscribed and composed of spindled to ovoid cells with abundant granular, eosinophilic cytoplasm and vesicular nuclei with small prominent nucleoli. Immunohistochemistry revealed reactivity only for NKI-C3 (11 of 12 cases), CD68 (7 of 11 cases), and NSE (5 of 10 cases); S-100 protein as well as other melanocytic, epithelial, and myoid markers were uniformly negative. All 13 of the lesions were locally excised and in the 8 cases with adequate follow-up ranging from 13 to 126 months (mean, 68 months; median, 41 months), none has recurred locally. However, one tumor (case no. 11) gave rise to a local lymph node metastasis 25 months after presentation, but the patient is currently disease-free 70 months after lymphadenectomy. These cutaneous granular tumors do not appear to be neural or Schwannian in nature, but their precise line of differentiation is unknown.

Granular cell atypical fibroxanthoma

We report on two patients with granular cell atypical fibroxanthoma. Both neoplasms were solitary, light-tan, dome-shaped papules on sun-exposed areas of the head in two elderly white men. Microscopically, these neoplasms showed a dermal proliferation of pleomorphic granular cells with irregular hyperchromatic nuclei, multinucleated cells, and scattered mitoses. Immunohistochemical stains were positive for CD68 and vimentin and negative for Melan-A or human melanoma black (HMB)-45, S-100 protein, pancytokeratin, and actin, consistent with atypical fibroxanthoma. The differential diagnosis of granular cells in neoplasms containing cytological pleomorphism is challenging in view of the many different neoplasms that may present with granular cytoplasm. These include the conventional granular cell tumor and its malignant form, leiomyoma, leiomyosarcoma, dermatofibroma, dermatofibrosarcoma protuberans, and angiosarcoma.

Atypical fibroxanthoma with prominent sclerosis

BACKGROUND

Malignant cutaneous spindle cell lesions with marked sclerosis are uncommon. Only a few cases of cutaneous leiomyosarcoma and dermatofibrosarcoma protuberans with sclerosis have been published.

METHODS

We report a case of atypical fibroxanthoma (AFX) with prominent sclerosis and hyalinization occurring on the scalp of an 81-year-old male.

RESULTS

Histopathologic examination revealed an exophytic, well-delineated, focally ulcerated tumor arising in sun-damaged skin. The lesion was composed of atypical spindle cells arranged in a fascicled and vaguely storiform pattern. Occasional multinucleated giant cells were present. The tumor cells were strongly positive for CD99 (O13), vimentin, and smooth muscle actin, and focally positive for CD68. There was striking sclerosis with hyalinization throughout the lesion.

CONCLUSIONS

Rarely, AFX may exhibit marked sclerosis with areas of complete replacement of tumor by hyalinized collagen. In a small biopsy, such hyalinization may be a diagnostic pitfall leading to an erroneous diagnosis.

Clear cell atypical fibroxanthoma:a clinicopathologic study

INTRODUCTION

The atypical fibroxanthoma (AFX) is considered by most authorities to represent a superficial or minimally invasive variant of malignant fibrous histiocytoma that most often presents as a solitary nodule on the sun-exposed skin of the elderly. Among the rarest variants is the clear cell AFX, a lesion which raises consideration to a differential diagnosis encompassing a variety of neoplastic and non-neoplastic clear cell proliferations.

METHODS

We describe three cases of a distinctive cutaneous neoplasm arising in the sun-exposed skin of elderly patients. In all cases, formalin-fixed, paraffin-embedded tissue was available for analysis. The histology in concert with the immunophenotype was held to be diagnostic of the clear cell variant of AFX.

RESULTS

All tumors comprised sheets of large cells with foamy cytoplasms and hyperchromatic, polyploid nuclei manifesting frequent and atypical mitoses. The critical cells in our cases expressed CD68 but none of CD3, CD20, CD34, S-100 protein, muscle-specific actin, factor XIIIa, Melan-A, carcinoembryonic antigen, or cytokeratin.

CONCLUSION

Although typical examples of AFX provoke diagnostic consideration of spindle cell cancers of the skin (most often spindle cell melanoma, spindle cell squamous cell carcinoma, and leiomyosarcoma), the clear cell variant raises other differential diagnostic considerations instead. These include balloon cell melanoma, sebaceous carcinoma, pleomorphic liposarcoma, chordoma, parachordoma, tricholemmal carcinoma and clear cell squamous cell carcinoma. A diagnosis of AFX is one of exclusion; one must employ immunohistochemical markers to rule out the aforementioned differential diagnostic considerations. By reporting the fifth, sixth and seventh cases of clear cell AFX, we hope to alert dermatopathologists to this distinctive and unusual neoplasm, recognition of which is essential to avoid under- or over-diagnosis and inappropriate therapy.